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forked from M-Labs/artiq
artiq/artiq/gateware/drtio/aux_controller.py

239 lines
8.4 KiB
Python

"""Auxiliary controller, common to satellite and master"""
from migen import *
from migen.fhdl.simplify import FullMemoryWE
from migen.genlib.cdc import MultiReg, PulseSynchronizer
from misoc.interconnect.csr import *
from misoc.interconnect import stream
from misoc.interconnect import wishbone
max_packet = 1024
aux_buffer_count = 8
class Transmitter(Module, AutoCSR):
def __init__(self, link_layer, min_mem_dw):
ll_dw = len(link_layer.tx_aux_data)
mem_dw = max(min_mem_dw, ll_dw)
self.aux_tx_length = CSRStorage(bits_for(max_packet),
alignment_bits=log2_int(mem_dw//8))
self.aux_tx = CSR()
self.specials.mem = Memory(mem_dw, max_packet//(mem_dw//8))
converter = stream.Converter(mem_dw, ll_dw)
self.submodules += converter
# when continuously fed, the Converter outputs data continuously
self.comb += [
converter.source.ack.eq(link_layer.tx_aux_ack),
link_layer.tx_aux_frame.eq(converter.source.stb),
link_layer.tx_aux_data.eq(converter.source.data)
]
seen_eop_rst = Signal()
frame_r = Signal()
seen_eop = Signal()
self.sync += [
If(link_layer.tx_aux_ack,
frame_r.eq(link_layer.tx_aux_frame),
If(frame_r & ~link_layer.tx_aux_frame, seen_eop.eq(1))
),
If(seen_eop_rst, seen_eop.eq(0))
]
mem_port = self.mem.get_port()
self.specials += mem_port
frame_counter_nbits = bits_for(max_packet) - log2_int(mem_dw//8)
frame_counter = Signal(frame_counter_nbits)
frame_counter_next = Signal(frame_counter_nbits)
frame_counter_ce = Signal()
frame_counter_rst = Signal()
self.comb += [
frame_counter_next.eq(frame_counter),
If(frame_counter_rst,
frame_counter_next.eq(0)
).Elif(frame_counter_ce,
frame_counter_next.eq(frame_counter + 1)
),
mem_port.adr.eq(frame_counter_next),
converter.sink.data.eq(mem_port.dat_r)
]
tx_done = Signal()
self.sync += [
frame_counter.eq(frame_counter_next),
If(self.aux_tx.re, self.aux_tx.w.eq(1)),
If(tx_done, self.aux_tx.w.eq(0))
]
fsm = FSM(reset_state="IDLE")
self.submodules += fsm
fsm.act("IDLE",
frame_counter_rst.eq(1),
seen_eop_rst.eq(1),
If(self.aux_tx.re, NextState("TRANSMIT"))
)
fsm.act("TRANSMIT",
converter.sink.stb.eq(1),
If(converter.sink.ack,
frame_counter_ce.eq(1)
),
If(frame_counter_next == self.aux_tx_length.storage,
NextState("WAIT_INTERFRAME"))
)
fsm.act("WAIT_INTERFRAME",
If(seen_eop,
tx_done.eq(1),
NextState("IDLE")
)
)
class Receiver(Module, AutoCSR):
def __init__(self, link_layer, min_mem_dw):
self.aux_rx_present = CSR()
self.aux_rx_error = CSR()
self.aux_read_pointer = CSR(log2_int(aux_buffer_count))
ll_dw = len(link_layer.rx_aux_data)
mem_dw = max(min_mem_dw, ll_dw)
self.specials.mem = Memory(mem_dw, aux_buffer_count*max_packet//(mem_dw//8))
converter = ClockDomainsRenamer("rtio_rx")(
stream.Converter(ll_dw, mem_dw))
self.submodules += converter
# when continuously drained, the Converter accepts data continuously
frame_r = Signal()
self.sync.rtio_rx += [
If(link_layer.rx_aux_stb,
frame_r.eq(link_layer.rx_aux_frame),
converter.sink.data.eq(link_layer.rx_aux_data)
)
]
self.comb += [
converter.sink.stb.eq(link_layer.rx_aux_stb & frame_r),
converter.sink.eop.eq(converter.sink.stb & ~link_layer.rx_aux_frame)
]
mem_port = self.mem.get_port(write_capable=True, clock_domain="rtio_rx")
self.specials += mem_port
# write pointer represents where the gateware is
write_pointer = Signal(log2_int(aux_buffer_count))
write_pointer_sys = Signal.like(write_pointer)
# read pointer represents where CPU is
# write reaching read is an error, read reaching write is buffer clear
read_pointer = Signal.like(write_pointer)
read_pointer_rx = Signal.like(write_pointer)
read_pointer.attr.add("no_retiming")
write_pointer.attr.add("no_retiming")
signal_error = PulseSynchronizer("rtio_rx", "sys")
self.specials += [
MultiReg(read_pointer, read_pointer_rx, "rtio_rx"),
MultiReg(write_pointer, write_pointer_sys)
]
frame_counter_nbits = bits_for(max_packet) - log2_int(mem_dw//8)
frame_counter = Signal(frame_counter_nbits)
# frame counter requires one more bit to represent overflow (bits_for)
# actual valid packet will be addressed with one bit less
packet_nbits = frame_counter_nbits - 1
self.comb += [
mem_port.adr[:packet_nbits].eq(frame_counter),
# bits above the frame counter point to current frame
mem_port.adr[packet_nbits:].eq(write_pointer),
mem_port.dat_w.eq(converter.source.data),
converter.source.ack.eq(1),
self.aux_read_pointer.w.eq(read_pointer)
]
self.submodules += signal_error
self.sync += [
If(self.aux_rx_error.re, self.aux_rx_error.w.eq(0)),
If(signal_error.o, self.aux_rx_error.w.eq(1)),
self.aux_rx_present.w.eq(~(read_pointer == write_pointer_sys)),
If(self.aux_rx_present.re & self.aux_rx_present.w,
read_pointer.eq(read_pointer + 1)),
]
fsm = ClockDomainsRenamer("rtio_rx")(FSM(reset_state="IDLE"))
self.submodules += fsm
sop = Signal(reset=1)
self.sync.rtio_rx += \
If(converter.source.stb,
If(converter.source.eop,
sop.eq(1)
).Else(
sop.eq(0)
)
)
fsm.act("IDLE",
If(converter.source.stb & sop,
NextValue(frame_counter, frame_counter + 1),
mem_port.we.eq(1),
If(converter.source.eop,
NextState("SIGNAL_FRAME")
).Else(
NextState("FRAME")
)
).Else(
NextValue(frame_counter, 0),
)
)
fsm.act("FRAME",
If(converter.source.stb,
NextValue(frame_counter, frame_counter + 1),
mem_port.we.eq(1),
If(frame_counter == max_packet,
mem_port.we.eq(0),
signal_error.i.eq(1),
NextState("IDLE") # discard the rest of the frame
),
If(converter.source.eop,
NextState("SIGNAL_FRAME")
)
)
)
fsm.act("SIGNAL_FRAME",
NextState("IDLE"),
If((write_pointer + 1) == read_pointer_rx,
# on full buffer, overwrite only current frame
signal_error.i.eq(1)
).Else(
NextValue(write_pointer, write_pointer + 1)
),
If(converter.source.stb, signal_error.i.eq(1))
)
# TODO: FullMemoryWE should be applied by migen.build
@FullMemoryWE()
class DRTIOAuxController(Module):
def __init__(self, link_layer, dw=32):
wsb = log2_int(dw//8)
self.bus = wishbone.Interface(data_width=dw, adr_width=32-wsb)
self.submodules.transmitter = Transmitter(link_layer, len(self.bus.dat_w))
self.submodules.receiver = Receiver(link_layer, len(self.bus.dat_w))
tx_sdram_if = wishbone.SRAM(self.transmitter.mem, read_only=False, data_width=dw)
rx_sdram_if = wishbone.SRAM(self.receiver.mem, read_only=True, data_width=dw)
decoder = wishbone.Decoder(self.bus,
[(lambda a: a[log2_int(max_packet*aux_buffer_count)-wsb] == 0, tx_sdram_if.bus),
(lambda a: a[log2_int(max_packet*aux_buffer_count)-wsb] == 1, rx_sdram_if.bus)],
register=True)
self.submodules += tx_sdram_if, rx_sdram_if, decoder
def get_csrs(self):
return self.transmitter.get_csrs() + self.receiver.get_csrs()